4 ms·

Highly unlikely unless such interference is very carefully, deliberately planned. If one did want to think adversarial one could explore a system receiving Lid

by ptero 10y ago

Highly unlikely unless such interference is very carefully, deliberately planned. If one did want to think adversarial one could explore a system receiving Lidar, say from a car behind, figuring out its transmission and doing your own illumination to confuse or jam the other car system. But the chances for this state arising naturally are astronomically small. My 2c.

abakker 10y ago
seems like you could make a material that would absorb most of the light, rather than rebounding it? Lidar uses NIR, or UV lasers, so if you could engineer a material that had good absorption properties maybe you could prevent the beams from rebounding and confuse it that way?
- blensor 10y ago
  You don't need to engineer it. In our lab tests we accidentially realized that one of our desktop computers was "invisible" to the Velodyne, because it had a black case. Every material that is black could be a good candidate. I am wondering if the google cars do have a problem with cars that have a matte black finish (those PVC foils). But you have to keep in mind that they are not invisible in the real sense, because you get a hole in your scan where you don't have points in your pointcloud. This could be detected, because the Velodyne usually has many beams pointing downward which eventually would hit the road, but would leave a hole instead if there is an NIR absorbing material. And if you use sensor fusion, you can use a camera to check for dark colors in those areas that might help you to detect such cases
  - Animats 10y ago
    The charcoal-black material sometimes used for office chair upholstery is a very good IR absorber, and those things are not visible to a SICK LIDAR. That's why you want to profile the road from a high LIDAR. It's not just about sensing obstacles. It's about building a height map of the environment. This was more important in the DARPA Grand Challenge, where we had to drive off-road. Potholes and rocks were to be expected. There are visual illusions for both vision and LIDAR, but few of them present the appearance of a flat road.
- Qworg 10y ago
  This is what happens sometimes, totally inadvertently.
blensor 10y ago
I am not 100% sure about that. At the moment it is basically impossible that there is interference from another LIDAR due to the fact that there are so few. but if every car, motorcycle, drone and whatnot is equipped with several LIDARS then interference might become real. Or it could at least cause the noise floor to be raised to a level where sensor readings are affected. But I am not saying that this will become a huge issue, because it would affect individual measurements, and the overall scan should be fine, just a bit noisier. And noise is something they have to deal with today as well due to different reflectance properties, electromagnetic interference, flying voxels, etc.
- ptero 10y ago
  Agree. Raising the noise floor is possible (but I suspect you need a lot of devices to do that perceptibly), but then it is usually relatively easy to adjust for, or at least detect the fact that you are in a higher noise environment.
gene-h 10y ago
There are commercially available systems for jamming speed measuring lidar used by police.[0] Although I am unsure if this would disrupt a line scanning lidar [0]https://en.wikipedia.org/wiki/Laser_jammer https://en.wikipedia.org/wiki/Laser_jammer

by ptero 10y ago

abakker 10y ago

seems like you could make a material that would absorb most of the light, rather than rebounding it? Lidar uses NIR, or UV lasers, so if you could engineer a material that had good absorption properties maybe you could prevent the beams from rebounding and confuse it that way?

blensor 10y ago
You don't need to engineer it. In our lab tests we accidentially realized that one of our desktop computers was "invisible" to the Velodyne, because it had a black case. Every material that is black could be a good candidate. I am wondering if the google cars do have a problem with cars that have a matte black finish (those PVC foils). But you have to keep in mind that they are not invisible in the real sense, because you get a hole in your scan where you don't have points in your pointcloud. This could be detected, because the Velodyne usually has many beams pointing downward which eventually would hit the road, but would leave a hole instead if there is an NIR absorbing material. And if you use sensor fusion, you can use a camera to check for dark colors in those areas that might help you to detect such cases
- Animats 10y ago
  The charcoal-black material sometimes used for office chair upholstery is a very good IR absorber, and those things are not visible to a SICK LIDAR. That's why you want to profile the road from a high LIDAR. It's not just about sensing obstacles. It's about building a height map of the environment. This was more important in the DARPA Grand Challenge, where we had to drive off-road. Potholes and rocks were to be expected. There are visual illusions for both vision and LIDAR, but few of them present the appearance of a flat road.
Qworg 10y ago
This is what happens sometimes, totally inadvertently.

blensor 10y ago

I am not 100% sure about that. At the moment it is basically impossible that there is interference from another LIDAR due to the fact that there are so few. but if every car, motorcycle, drone and whatnot is equipped with several LIDARS then interference might become real. Or it could at least cause the noise floor to be raised to a level where sensor readings are affected. But I am not saying that this will become a huge issue, because it would affect individual measurements, and the overall scan should be fine, just a bit noisier. And noise is something they have to deal with today as well due to different reflectance properties, electromagnetic interference, flying voxels, etc.

ptero 10y ago
Agree. Raising the noise floor is possible (but I suspect you need a lot of devices to do that perceptibly), but then it is usually relatively easy to adjust for, or at least detect the fact that you are in a higher noise environment.

gene-h 10y ago

There are commercially available systems for jamming speed measuring lidar used by police.[0] Although I am unsure if this would disrupt a line scanning lidar [0]https://en.wikipedia.org/wiki/Laser_jammer https://en.wikipedia.org/wiki/Laser_jammer